SHORT REPORT: LACK OF SEX EFFECT ON THE PHARMACOKINETICS OF PRIMAQUINE

Abstract. The pharmacokinetics of primaquine have been well defined in male volunteers, but there is little data on the disposition of the drug in women. We compared the kinetics of primaquine in nine male and nine female healthy Australian volunteers after the administration of a single oral dose (30 mg base) of primaquine. No statistical differences were observed in the following kinetic parameters of primaquine between men and women, respectively: maximum plasma concentration (93 ± 26 and 115 ± 38 ng/mL; 95 % confidence interval [CI] of the mean difference: −55 to 10 ng/mL; P 0.16), area under the curve (1.1 ± 0.5 and 1.2 ± 0.4 g.h/mL; 95 % CI: −0.6 to 0.3 g.h/mL; P 0.54), and clearance (0.34 ± 0.12 and 0.39 ± 0.14 L/h/kg; 95 % CI: −0.17 to 0.08 L/h/kg; P 0.46). The clinical relevance of such findings would suggest that sex does not have to be taken into account as a factor when prescribing primaquine for radical cure or terminal prophylaxis of Plasmodium vivax malaria. Plasmodium vivax affects about 100 million people each year in tropical areas and is an important cause of morbidity in the Americas, the Western Pacific, and Asia.1 Primaquine (Weifa A.S., Kragero, Norway), an 8-aminoquinoline, is the only drug available for radical cure and terminal prophylaxis of P. vivax. It is also a highly effective prophylactic agen